High frequency system



May 28, 1940. E. GOSSEL ET'AL 2,202,487

HIGH FREQUENCY SYSTEM Fi led Fb. 25, 1938 Patented May 28,1940

UNITED STATES PATENT OFFICE many, assignors to C. Lorenz Aktiengesellschaft, Berlin-Tempelhof, Germany, a com- Application February 25, 1938, Serial No. 192,568 In Germany February 25, 1937 2 Claims.

The present invention relates to high frequency 1 systems, and particularly to improvements in generating and receiving ultra-short waves.

It is well known that high frequency oscillations, e. g., having wave lengths of fractions of meters or decimeters, may be generated by means of oscillatory circuits comprising one inductance coil. These oscillatory circuits are connected to the grid and the anode of a thermionic valve and I0 correspond to Hartley circuits, the capacities of which are formed by the inherent capacities of a the tubes. The inductance coil of such an oscillatory circuit generally provides the shape of a bail, e. g., adjustable in the same manner as a trombone slide. I

The present invention deals with an arrangement for generating. and receiving very short waves and has for its object to increase the power of the high frequency generated. This is accomplished by the provision of a metallic plate in close proximity to the inductance coil of the oscillatory circuit, said plate being so connected that the resonance resistance of the anode circuit is increased. The effect of this arrangement is substantially based upon the fact that the metallic plate introduces a transmission gain, while on the other hand an additional self-inductance is set up by virtue of the metallic plate being introduced in the circuit arrangement. The resulting circuit thus obtained increases the resonance resistance of the anode circuit which is in turn matched to the inherent resistance of the tube. The invention will be clearly understood from the following description taken in conjunction with the accompanyng drawing, in which- Fig. 1 representsa top view of one embodiment according to the invention; Fig. 2 is a section on the line 2--2 of Fig. 1; while Fig. 3 illustrates a wiring diagram according to the invention.

With reference to Figs. 1 and 2, a frontal plate I provided in any suitable manner in thecasing of an equipment carries a valve 2, e. g., of the known acorn shape. A bailshaped inductance 3 is connected between the grid and the anode of the tube 2. The anode voltage from the source 8 is supplied to this tube through a strap-shaped lead-inconductor 4 and a metallic plate 5 which according to the invention is positioned at a short distance, less than one-quarter of the operating wave length from the inductance 3. The shape of the plate is not critical for the invention.

- A preferred arrangement is to provide a plane plate parallel to the inductance of the oscillatory circuit at a given distance therefrom.

A wiring diagram according to Fig. 3 shows that the inductance 3 and a blocking condenser 6 are connected in series between the grid and the anode of the valve 2. The gridis connected to the cathode through a leak resistance 1. The current source 8 applies the anode voltage through the plate 5 and a choke 4, which latter sheet metal.

The oscillatory circuit is coupled to an antenna over a coupling member (not shown). v

The arrangement above described is applicable in the same manner for the purpose of transmission and/or reception of ultra-short waves.

What is claimed is:

1. In a circuit arrangement for ultra-short wave oscillations, an electric discharge device having an anode, a cathode and a grid, an oscillatory circuit comprising an inductance and capacitance between said anode and grid, a metal plate, distant from said inductance by less than one-quarter wave length at the resonance frequency of said circuit, a. choke, and an anode voltage source connected to .the anode through said choke and metal plate.

2. The arrangement according to claim 1 and in which said choke is an arcuate piece of sheet metal extending from .the inductance to the metal plate.

' ERICH GOSSE-L.

WERNER PUHLMANN.

' may be constituted by a strap-shaped piece of 20 

